Mariscos Ruben: Claw and Fin and Chiltepin

The Sea of Cortez teems with ocean life, the likes of which we only see here when chefs cart the haul north of the border.Chocolata and pata de mula (ark) clams, snook, perfect sweet shrimp, all come out of the water also known as the Gulf of California, and it's with Baja California that most of the take is identified: La Paz for the clams, San Felipe for the shrimp, Cabo San Lucas (and Mazatlán, Sinaloa) for the snook. Poor Sonora, on the east side of the sea, has a reputation for grilled meat and flour tortillas.

Mariscos Ruben, though, in a gritty-looking (but perfectly safe) part of downtown Tijuana between the Mercado Hidalgo and the clubs of 6th St., aims to change that. It's a huge operation for a mobile eatery, with a permanent building, a truck, and a huge awning connecting the two, allowing you to eat in the shade, and they are proudly Sonoran. All you have to do is ask about the provenance of the seafood, and they'll talk about the arid shores that teem with underwater life waiting for lucky people like you to stop by and eat.

Sonora is also the home of the chiltepin, a small, bomb-shaped chile that blasts your mouth with a few milliseconds of intense, explosive capsaicin burn before fading away to a sweet finish, and Ruben's truck has a beautiful salsa de chiltepin. While there's an array of homemade and bottled salsas on the table against the shed, the bright red chiltepin salsa has pride of place on the counter at the truck. Pair it with anything that contains shrimp; the blast of spice primes the tongue perfectly for the sweetness of Sea of Cortez shrimp.

Dave Lieberman

Order an aguachile, with clams, with shrimp, or with crab claws; you'll be given an enormous, heavy molcajete full of brick-red sludge (even redder if you have pata de mula clams in your aguachile, like the picture above) that contains an intensely spicy sauce (aguachile means "pepper water", after all), ready to slick down the seafood and set it alight with cold fire. The secret to Ruben's perfect aguachile is the size of the seafood; they only use pieces of seafood that are large enough to stand up to the chile sauce.

Dave Lieberman

The thing you should be eating, though--the thing to order even when Tijuana is baking under the devil winds as it is this time of year--is cahuamanta. This is Mexican gumbo: slightly spicy, dark with roux, thick with chopped vegetables, flecked with green herbs, overflowing with springy pieces of skate wing. It's a surprisingly substantial meal: the portion served at Ruben's is enough to keep you full for several hours.

Find Mariscos Ruben at the corner of Calle Octava (8th St.) and Quintana Roo, just a block toward downtown from Taquería Franc and two blocks from Mercado Hidalgo. Officially, they are open 10 a.m. to 6 p.m., but many times the ladies are there taking orders as early as 8 a.m., particularly on weekends.